I think that you should tell him exactly what you have written here.  You should of course focus on the positive parts of your relationship, and if you both feel the same way, that there is only this relationship, and that you have to do what it takes to make it work, then I think that you have another conversation to have.  3 hours is of course better than living in another country, but on the other hand, it sounds to me like you guys need to think long and hard about how you can live together, and how you can make changes in your lives in order to make things easier on the relationship.  Sacrifices are needed for love, and I think that you can make this work.  You both just have to be willing to do what it takes.